1. Technical Field
The disclosure relates to a touch sensor structure and fabricating method thereof, and more particularly to a projective capacitive touch sensor structure and fabricating method thereof.
2. Background
The trend of display technology development gradually heads toward man-machine interface with more humanity. The conventional input interface were mostly operated with mechanical buttons. However, as the rise of flat displays, touch panels have now become the main stream in the market by replacing input devices such as keyboards, mice, and so on, such that various information apparatuses are more used friendly. Thus, the timing of touch panels for input interface has come. For example, these touch panels can be adopted in automobile navigation, game consoles, public information systems (e.g. vending machines, automatic teller machines (ATMs), tour guide systems, industrial use, small electronic products (e.g. personal digital assistants (PDAs), e-books and so on. The touch panel industry is highly competitive, and the manufacturers are mainly in Japan, Taiwan, the United States of America, Korea, and China. Manufactures in the world are actively involved in this touch field and the market demand for touch panels is expected to increase tremendously in the next few years.
With the overwhelming popularity of iPhone, the global sale of smart phones has increased rapidly. Manufacturers do not dare to underestimate the market potential of smart phones in hardware apparatuses and application services and have prepared themselves to take the market share. Projective capacitive touch panels thus develop in an explosive manner and more manufacturers specialized in touch panels have themselves involved in the development and production of multi-touch technology.
Conventional projective capacitive touch panels are constituted by a dual-substrate structure, where the X and Y sensor units are respectively disposed on two different surface of substrates. The dual-substrate structure may lead to misalignment. The misalignment leads to insensitive touch signals and lower precision. Further, other than the massive structure of the double-layer structure, as the X and the Y axis sensor units on the different planes have a higher hollow ratio, non-uniform light transmittance results in a visible range which leads to image distortion.
In order to solve the issues derived from the projective capacitive touch panel having the dual-substrate structure, the projective capacitive touch panel now applies the structural design of a projective capacitive touch panel having a single substrate. In the projective capacitive touch panel having the single substrate structure, an X and a Y axis sensor units are disposed on the same plane respectively to greatly reduce the hollow ratio and the problem of the vertical alignment, such that better images, higher sensitivity and precision can be obtained. Furthermore, the design of the single substrate also leads to weight reduction and miniaturization.
The fabricating process of the conventional projective capacitive touch panel having the single substrate structure is very complicated as follows. A patterning process of the X and the Y axis sensor units on the same plane is performed on a transparent conductive substrate. A dielectric insulating layer is deposited on the X and the Y axis sensor units by using a vacuum deposition method, and then a structure required by a bridging wire is formed by performing a photolithography process and a etching process to the dielectric insulating layer. A metal layer is deposited on the dielectric insulating layer structure by using a vacuum deposition method, and then the bridging wire is formed by performing a photolithography process and a etching process to the metal layer. As mentioned above, serial and complicated vacuum deposition processes, photolithography processes and etching processes are required in the conventional process. Therefore, the disclosure provides a projective capacitive touch panel having the single substrate structure which can simplify the process.